Brake



H. C. BOWEN April 9, 1940.

BRAKE Filed Dec. 3, 1938 IN VENTOR. Bamsw gseaierd 72 q 2.

ATTORNEY.

Patented Apr. 9 1940 PATENT oFrI-cE BRAKE Herbert 0. Bowen, Detroit, Mich, assignor to Hydraulic Brake Company, Detroit, Mich, a corporation of California Application December 3, 1938, Serial No. 243,865

9 Claims.

This invention relates to brakes, and more particularly to brakes for motor vehicles.

Broadly the invention comprehends a brake structure of the type wherein a part of the brak ing force of one braking element or shoe is transferred to the other braking element or shoe so as to improve the efl'ectiveness of the brake as a whole. 7

'An object of the invention is to provide a brake constructed and operated in such a manner as to save pedaltravel.

Another object of the invention is to provide a brake wherein more effective control of the forward braking element may be attained.

Another object of the invention is to provide a brake wherein a part of the braking force of the forward braking shoe may be transferred to the trailing or reverse braking shoe.

A further objectof the invention is to provide i a brake of the type wherein the forward brakingin connection with the drawing forming a part of this specification, and in which- Fig. 1 is a vertical sectional view of a brake taken just back of the head of the drum illustrating the invention as applied;

Fig. 2 is a sectional view substantially on line 2-2, Fig. ;]and

Fig. 3 is a sectional view 3-3, Fig. 1. i Referring to the drawing for more specific details of the invention, l0 represents a fixed support or backing plate adapted to be secured to an axle or an axle housing, not shown, and I2 represents a rotatable drum associated with the i backing plate and adapted to be secured to a wheel, not shown.

The backing plate has arranged thereon diametrically disposed adjustable anchors l4 and l6, 7 also an adjustable retractile stop l8. A lever has its fulcrumed end pivotally mounted on the anchor l4, and slidably mounted on the lever is a braking shoe 22.

substantially on line Asshown, the shoe 22 has a channeled web 24' 32, and when in retracted position the shoe is supported by the retractile stop IS.

A shoe 34 shiftably mounted on theanchor l6 includes a web 36 having a slot 38 receiving the anchor and a rim 4!] supported on the'web hav- 5 ing secured thereto a lining 42-suitable for cooperation with the drum. The shoe 34 is supported on the backing plate as by a conventional steady rest 44, and connected by an adjustable link 46 to the sliding shoe 22.

The shoes 22 and 34 are connected by a retractile spring 48, and the shoe 34 is connected by springs 50 and 52 to fixed supports 54 and 56. The spring 48 serves to return the shoes to their retracted position'upon conclusion of a braking l5 operation, the spring 50 serves to lift the shoe 34 against its anchor l6, and the spring 52 serves to return the shiftable shoe.22 to its retracted position. I V

The shoes are actuated by a conventional fluid 2o pressure actuated motor 53 mounted on the backing plate l0 and suitably connected to the force-applying end of the lever 20 and the force applying end of the shoe 34.

In a normal forward braking operation, upon energization of the motor 58, the shoes 22 and 34 are moved from their retracted position into engagement with the drum l2 against the resistance of the retractile spring 48. When the shoe 22 engages the drum l2, due to the wiping action of the drum, the shoe is slightly shifted on the lever- 20 circumferentially with respect. to the drum. During this movement the shoe slides on the anchor I4 and is guided thereby to inhibit radially outward movement of the anchored end of the shoe so as to avoid building up excessive pressure at the heel of the shoe.

The applied actuating force of the shoe 22, augmented by the wiping action of the drum I2, is partly transmitted from the shoe 22 through the adjustable link 46 to the toe of the shoe 34, so as to apply the shoe 34 with increased effectiveness. Theshoe 22 functions as a servo shoe, controlled so as to provide a smooth operation.

Upon concluding this braking operation, the applied actuating force is released. This results in the motor 58 and the shoes 22 and 34 returning to their retracted position under the influence of the spring 48. The spring serves to lift the shoe 34 against its anchor I6, andthe 5o spring 52 imposes force on the toe of the shoe 34, and this force is transmitted through the; link 46 to the shoe 22, resulting in movement oft the shoe '22 against its anchor l4. i In a reverse braking operation, upon energizar tion of the motor 68, the shoes 22 and M are moved from their retracted position into engagement with the drum l2 against the resistance of the retractile spring 48. When the shoes engage the drum, the shoe 3d moves from its anchor 56 and becomes in effect a servo shoe, transmitting force therefrom through the link G6 tothe heel of the shoe 22 so as to apply the shoe 22 with increased effectiveness. Upon conclusion of this braking operation, the brake returns to the position of rest, as hereinahove described in connection with a forward braking operation.

While this invention has been described in connection with certain specific embodiments, the principle involved is susceptible of numerous other applications that will readily occur to persons skilled in the art. The invention is, therefore, to be limited only as indicated by the scope of the appended claims.

Having thus described the various features of the invention, what I claim as new and desire to secure by Letters Patent is:

1. A brake comprising a fixed support, an anchor thereon, a lever fulcrumed on the anchor, a shoe slidable on the lever having a slot receiving the anchor, and means for actuating the lever.

2. A brake comprising a fixed support, a drum associated therewith, an anchor on the support, a lever fulcrumed on the anchor, a shoe slidable on the lever having a slot receiving the anchor, a shoe slidably anchored on the support, a link connecting the shoes, and means for actuating the lever and the shoe anchored on the support.

3. A brake comprising a fixed support, a rotatable drum associated therewith, an anchor on the support, a lever fulcrumed on the anchor, a shoe embracing the lever and slidable thereon having a slot receiving the anchor, a shoe shiftably anchored on the fixed support, a link connecting the shoes, and means for actuating the shoes.

4. A brake comprising a fixed support, a rotatable drum associated therewith, a lever pivoted on the support, a shoe slidable on the lever, a shoe shiftably anchored on the support, a link connecting the shoe on the lever to the shiftably anchored shoe, and means for actuating the lever and shiftably anchored shoe.

5. A brake comprising a fixed support, a rotatable drum associated therewith, diametrically disposed anchors on the support, a lever pivotally %,i@d,$8t3

' mounted on one of the anchors, a shoe slidable on the lever having a slot receiving the anchor, a shoe shiftably mounted on the other anchor, a link connecting the shoes, and means for actuating the lever and the last-mentioned shoe.

6. A brake comprising a fixed support, a rotatable drum associated therewith, diametrically disposed anchors on the fixed support, a lever fulcrumed on one of the anchors, a shoe shiftably mounted on the other anchor, a shoe slidable on the lever, a link connecting the shoes, and means for actuating the lever and the shiftably mounted shoe.

7. A brake comprising a fixed support, a drum associated therewith, diametrically disposed anchors on the support, a lever fulcrumed on one of the anchors, a shoe shiftably mounted on the other anchor, a shoe slidable on the lever having a slot receiving the anchor constituting the fulcrum for the lever, a link connecting the shoe on the lever to the unanchored end of the shiftably mounted shoe, and a motor for actuating the lever and the shiftably mounted shoe.

8. A brake comprising a fixed support, a rotatable drum associated therewith, a pair of diametrically disposed anchors on the support, a lever fulcrumed on one of the anchors, a shoe shiftably mounted on the other anchor, a shoe having a channeled web embracing the lever and slidable thereon, said shoe being shiftably anchored on the anchor constituting the fulcrum of the shoe, a link connecting the shoe on the lever to the unanchored end of the other shoe, and a motor for actuating the lever and the shiftably anchored shoe.

9. A brake comprising a fixed support, a rotatable drum associated therewith, a pair of diametrically disposed anchors on the support, a lever fulcrumed on one of the anchors, a shoe shiftably mounted on the other anchor, a shoe having a channeled web straddling the lever, said last mentioned shoe slidable on the lever and shiftably anchored on the anchor constituting the fulcrum for the lever, an adjustable link connecting the shoe on the lever to the unanchored end of the other shoe, and a motor for actuating the lever and the shoe shiftably anchored on the support.

HERBERT C. BOWEN. 

